The present invention relates to a convertible bench and table assembly, and more particularly to an assembly wherein a frame is provided upon which a seat portion is fixed in position. The assembly also includes a common portion movably mounted on the frame for movement between an unlocked position where it is maintained by gravity to form a seat back and a locked position where it forms a table top. This invention is an improvement over similar assemblies shown in U.S. Pat. Nos. 4,194,784 and 4,913,488, the disclosures of which are incorporated herein by reference.
In the structures shown in the above-referenced patents, a movable locking member is provided at each end of the common portion, each locking member including a wedge portion adapted to be wedged between an upstanding frame portion and a support means which forms part of the common portion. In the construction of U.S. Pat. No. 4,194,784, the locking member incorporated a wedge portion for performing the function of locking the common portion in position. However, this arrangement did not prove entirely satisfactory. The construction of U.S. Pat No. 4,913,488 introduced additional means to maintain the locking member in locked position in the form of a projection defining a detent on the locking member which cooperates with a rib formed on the support means of the common portion.
The improved construction of U.S. Pat No. 4,913,488 has presented serious problems in use. A first problem is caused by the fact that the locking member is slidably disposed within a support means having walls which effectively hide the locking member from view so that a user cannot readily visibly determine whether the locking member is in fully locked position. The user must judge the degree of engagement of the detent with the rib more or less by feel, and with only fingertip contact with a small actuator. In fact, depending on the tolerances of the molded components, contact of the projection on the locking member with the rib can be inadvertently interpreted as a "stop" upon coming into contact with one another due to the tightness of their interference. Therefore, the user could believe that the common portion will be retained in locked in position, when, in reality, the detent and rib serve no such function. In other words, the user cannot readily ascertain that the common portion is securely retained in its locked position by feel or by any readily visible means.
A further problem with the construction shown in U.S. Pat No. 4,913,488 is that the projection on the locking member and the rib on the support means of the common portion may actually have little or no contact with one another because of the small size thereof, and improper or incomplete molding. Furthermore, the wooden members of the common portion tend to twist and warp with the passage of time, thereby deforming the support means of the common portion which causes the projection and the rib to be pulled out of contact with one another.